Video monitoring system using daisy chain

ABSTRACT

A video monitoring system using daisy chain is disclosed. A video monitoring system uses daisy chain, which can display more than four divided screens on one display screen with a simple configuration of the video monitoring system by bypassing video signals captured by a plurality of video cameras through many stages.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation-in-part of the earlier filed non-provisional application, having U.S. application Ser. No. 10/332,207, filed on Jan. 3, 2003, which is incorporated herein in its entirety.

FIELD OF THE INVENTION

The present invention relates to a video monitoring system, and more particularly to a video monitoring system using daisy chain.

DESCRIPTION OF THE RELATED ART

A conventional video monitoring system is installed in a general house, department store, bank, factory, exhibition hall, etc. to monitor visitors and prevent a burglary. The conventional video monitoring system comprises a plurality of video cameras for capturing video signals corresponding to objects of monitored areas, a signal processor for processing video signals captured by video cameras, and a video display device for displaying video images corresponding to the processed video signals on one display screen having divided display screens.

The conventional video monitoring system reduces video data corresponding to video signals captured by four video cameras according to a scaling reduction ratio and displays video images corresponding to the reduced video data on the one display screen containing four divided screens. Here, the one display screen containing the four divided screens is referred to as a quad screen. According to a quad screen combination, video images corresponding to video signals inputted from video cameras can be displayed on the four divided display screens, eight divided display screens or sixteen divided display screens divided within one full display screen.

For example, where video signals can be displayed on the sixteen divided screens on the basis of the quad screen combination, four quad units QUAD1-QUAD4 are configured as shown in FIG. 1. In this case, frame memories fm1-fm4 are provided to configure the respective quad screens. A frame memory fm5 and a quad unit QUAD5 are provided to combine quad video data from the four quad units QUAD1-QUAD4 to process the combined quad video data so that sixteen video images corresponding to the processed video data are displayed on the sixteen divided screens.

Therefore, as the number of quad units is increased, the number of frame memories is increased in order to configure the sixteen divided screens. A last stage of the conventional video monitoring system includes another quad unit QUADS for processing the quad video data from the respective quad units in addition to the four quad units QUAD1-QUAD4 and another frame memory fm5 for configuring the sixteen divided screens in addition to the frame memories fm1-fm4. There is a problem in that a configuration of the conventional video monitoring system is complicated to configure with more than the four divided screens, and costs for system construction are increased.

SUMMARY OF THE INVENTION

Therefore, the present invention has been made in view of the above problems, and the present invention provides a video monitoring system using daisy chain, which can display more than four divided screens on one display screen with a simple configuration of the video monitoring system by bypassing video signals captured by a plurality of video cameras through many stages.

The present invention also provides a video monitoring system using daisy chain, which can display a plurality of channel video images on divided screens within one display screen by arbitrarily extending the number of divided screens with a single memory.

In accordance with an aspect of the present invention, a video monitoring system for configuring and displaying one or more divided screens corresponding to one or more video signals captured by one or more cameras, comprises:

A/D (Analog/Digital) converters for converting channel video signals outputted from the video cameras into digital video data;

-   -   one or more slave video signal processors coupled by daisy chain         for reducing the digital video data of each channel outputted         from the A/D converters through a video source channel,         collecting the digital video data of the video source channel         outputted through a first bypass channel placed at a front stage         of a slave video signal processor and the digital video data of         the video source channel outputted through a second bypass         channel placed at the front stage of the slave video signal         processor, and outputting the collected video data to the second         bypass channel;     -   a master video signal processor for reducing another digital         video data outputted from the A/D converters through the video         source channel, recording another digital video data and the         digital video data outputted from the first bypass channel and         the second bypass channel coupled to a last slave video signal         processor among the slave video signal processors, in a frame         memory, and configuring and outputting video data corresponding         to multiple channel divided screens; and     -   a D/A (Digital/Analog) converter for converting the video data         corresponding to the multiple channel divided screens into         analog video signals and outputting the analog video signals to         a video display device.

The slave video signal processor reduces the digital video data of the video source channel corresponding to the video signals captured by each video camera and then outputs the reduced digital video data. The slave video signal processor bypasses the digital video data from another slave video signal processor placed at its front stage, thereby outputting the bypassed digital video data to another slave video signal processor placed at its rear stage. The master video signal processor may record the digital video data of the video source channel corresponding to the video signals captured by respective video cameras and the digital video data bypassed from the slave video signal processor placed at its front stage in the frame memory, thereby configuring multiple channel divided screens and then outputting the configured multiple channel divided screens. Therefore, the video monitoring system may display the multiple channel divided screens with a simple configuration of the system.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a view showing a configuration of a conventional video monitoring system including a plurality of quad units;

FIG. 2 is a view showing a configuration of a video monitoring system using daisy chain in accordance with a first embodiment of the present invention;

FIG. 3 is a block diagram illustrating a video signal processor for implementing the video monitoring system shown in FIG. 2;

FIG. 4 is a view explaining a signal transfer procedure when the video signal processor shown in FIG. 3 is employed as a slave video signal processor;

FIG. 5 is a view explaining a signal transfer procedure when the video signal processor shown in FIG. 3 is employed as a master video signal processor;

FIG. 6 is a view showing a configuration of a video monitoring system using daisy chain in accordance with a second embodiment of the present invention; and

FIG. 7 is a view showing a configuration of a video monitoring system using daisy chain in accordance with a third embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Now, exemplary embodiments of the present invention will be described in detail with reference to the annexed drawings. In the following description, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

FIG. 2 is a view showing a configuration of a video monitoring system using daisy chain in accordance with a first embodiment of the present invention. In more detail, FIG. 2 is a view showing a configuration of a video monitoring system for displaying sixteen divided display screens on a video display device.

As shown in FIG. 2, the video monitoring system for displaying the sixteen divided display screens comprises three slave video signal processors 18, 20 and 22 and one master video signal processor 24. The slave video signal processors 18, 20 and 22 and master video signal processor 24 will be described below and can be composed of the same components as one another.

Referring to FIG. 2, A/D (Analog/Digital) converters 10, 12, 14 and 16 are coupled to video source channels of the slave video signal processors 18, 20 and 22 and master video signal processor 24. The A/D (Analog/Digital) converters 10, 12, 14 and 16 convert channel video signals outputted from video cameras vc1-vc16 into digital video data.

The slave video signal processors 18, 20 and 22 reduce the digital video data of each channel outputted from the A/D converters 10, 12 and 14 through the video source channels and then output the reduced digital video data to a first bypass channel V1, V3 and V5. The slave video signal processors 18, 20 and 22 collect the digital video data of the video source channels outputted through the first bypass channel N.C., V1 and V3 and the digital video data outputted through a second bypass channel N.C., V2 and V4 and then output the collected digital video data to the second bypass channel V2, V4 and V6, respectively. The slave video signal processors 18, 20 and 22 are coupled to one another by the daisy chain.

The master video signal processor 24 reduces the digital video data outputted from the A/D converters 16 through a video source channel. The master video signal processor 24 records the digital video data outputted from the first bypass channel V5 and the second bypass channel V6 coupled to the third slave video signal processor 22, placed at a front stage of the master video signal processor 24 to be described below, in a frame memory 26. The frame memory 26 stores the digital video data for configuring multiple divided display screens. For reference, a memory controller equipped with the master video signal processor 24 controls access to the frame memory 26.

A D/A (Digital/Analog) converter 28 converts the video data corresponding to the multiple divided display screens outputted from the master video signal processor 24 into analog video signals. For reference, “N.C.” of FIG. 1 is an abbreviation of “No Connection”. Configurations of the slave video signal processors 18, 20 and 22 and master video signal processor 24 in the video monitoring system will be described below in detail.

FIG. 3 is a block diagram illustrating a master or slave video signal processor for implementing the video monitoring system shown in FIG. 2. In accordance with an embodiment of the present invention, the slave video signal processors 18, 20 and 22 and master video signal processor 24 comprise video input controllers 30, horizontal/vertical scalers 32, input buffers 34, a memory controller 36, an output buffer 38, a video output controller 40 and a bypass buffer 42, respectively, as shown in FIG. 2.

The video input controllers 30 extend digital video data outputted from the A/D converters 10 coupled to the video source channel, and separate and control horizontal and vertical synchronous signals.

After receiving digital video data outputted from each of the A/D converters 10 coupled to the video source channel, the video input controllers 30 separate the digital video data into luminance component data and chrominance component data to expand a data bus. That is, the luminance component and the chrominance component of the video data, when inputted, are contained in one bus in a time-sharing manner, but are separated from each other and individually outputted in 8-bit bus by the video input controllers 30. In addition, the video input controllers 30 extract and output horizontal and vertical synchronous signals which are then used for image size reduction or divided image synthesis. In the video signal processors, the number of video input controllers 30 is the same as the number of A/D converters 10.

The horizontal/vertical scalers 32 downscale a screen on which to display the digital video data outputted from the video input controllers 30, in a horizontal direction and/or a vertical direction so that the digital video data outputted from the video input controllers 30 can be stored to be displayed on divided display screens. It is clear that the horizontal/vertical scalers 32 reduce the digital video data by performing interpolation between adjacent digital video data on the basis of reduction ratios. The reduction ratios in the horizontal and vertical directions can be varied on the basis of the number of divided display screens to be displayed on a video display device. For instance, a final display of a 4-division screen can be achieved through reduction by half in both a horizontal and a vertical direction and, in the case of a 16-division screen, quarter reduction is performed in both a horizontal and a vertical direction. In the embodiment of the present invention, it is assumed that each slave video signal processor configures the four divided display screens. In the video signal processors, the number of horizontal/vertical scalers 32 is the same as the number of video cameras.

The input buffer 34 temporarily stores the video data outputted from the horizontal/vertical scalers 32 and then outputs the video data through two channels. One of the two channels is a first bypass channel (Bypass video Out) and the other channel is needed in the memory controller 36 reading the video data.

The memory controller 36 reads the screen-downscaled digital video data from the input buffer 34 in burst units_and records the read video data at frame memory addresses designated channel by channel. The digital image data collected from the bypass buffer 42 is recorded at the designated frame memory addresses to configure multi-channel divided screen data. The recorded video data is read out so that it can be displayed in real time. In accordance with the present invention, the slave video signal processors 18, 20 and 22 are not directly connected to the memory controller 36 and only the master video signal processor 24 is directly connected to the memory controller 36. In the slave video signal processor 18, 20 and 22, accordingly, a video signal is directly outputted, in its current state, from the input buffer 34 to the first bypass video channel (Bypass video out) without using the memory controller 36.

The output buffer 38 temporarily stores the video data corresponding to one display screen. The video output controller 40 combines supplementary information (including time information, channel information, etc.) with the video data of the one display screen outputted from the output buffer 38 to output the supplementary information and the video data. The video data outputted from the video output controller 40 is converted into analog video signals by the D/A converter 28 and then the analog video signals are outputted to the video display device.

At last, the bypass buffer 42 receives the video data from a first bypass channel (Bypass Video In) and a second bypass channel (Bypass Video In) coupled to a slave video signal processor placed at its front stage and then, outputs the stored video data through one channel in a time division multiplexing manner. That is, without undergoing a process such as the synthesis of divided images, the data is directly outputted. At this time, the data is outputted into the memory controller 36 when it is used in the master video signal processor or into the first bypass channel when it is used in the slave video signal processor.

As described above, the slave video signal processors 18, 20 and 22 and the master video signal processor 24 in accordance with the embodiment of the present invention can be composed of the same components as one another. However, where the video signal processor is employed as the slave video signal processor, it can employ only the video data outputted through the first bypass channel coupled to an output terminal of the input buffer 34.

FIG. 4 is a view explaining a signal transfer procedure when the video signal processor shown in FIG. 3 is employed as a slave video signal processor. FIG. 5 is a view explaining a signal transfer procedure when the video signal processor shown in FIG. 3 is employed as a master video signal processor.

In other words, when the video signal processor shown in FIG. 3 is employed as the slave video signal processor, the digital video data inputted through the video source channels is transferred to another slave video signal processor or the master video signal processor placed at the rear stage of the slave video signal processor through a video input controller 30, a horizontal/vertical scaler 32, an input buffer 34 and a first bypass channel (Bypass Video Out). Then, the slave video signal processor collects the digital video data inputted through the first bypass channel and a second bypass channel coupled to another slave video signal processor placed at its front stage and then outputs it through the second bypass channel. That is, because the slave video signal processor collects the video data inputted through the video source channel placed at its front stage, it can be configured as shown in FIG. 4 or FIG. 3. Herein, to collect digital video data means that the digital video data is outputted in its current state after order adjustment alone, without actually undergoing a processing procedure. For instance, inputted data is outputted in a multiplexing manner.

The video signal processor shown in FIG. 5 represents the case in which the video signal processor shown in FIG. 3 is operated as the master video signal processor. Video signals outputted from video cameras vc13-vc16 are inputted into a video source channel through A/D converters 10. Then, the digital video data inputted through the video source channels is stored in a frame memory 26 through video input controllers 30, horizontal/vertical scalers 32 and input buffers 34. The digital video data outputted through bypass channels V5 and V6, coupled to another slave video signal processor placed at the front stage of the video signal processor shown in FIG. 5, is stored in the frame memory 26 through a bypass buffer 42 by a frame controller 36. Accordingly, the video data stored in the frame memory 26 is controlled by the memory controller 36 and externally outputted through an output buffer 38 and video output controller 40.

The operation of the video monitoring system shown in FIG. 2 where the slave video signal processors 18, 20 and 22 and the master video signal processor 24 are coupled by the daisy chain will be described below.

First, video signals captured by four video cameras vc1-vc4 are converted into digital video data by A/D converters 10. Then, the digital video data is inputted into a video source channel coupled to the slave video signal processor 18. Then, the slave video signal processor 18 reduces and outputs the video data appropriate to configure the four divided display screens. The reduced video data is outputted to a first bypass channel V1 through input buffers 34 and then transferred to the slave video signal processor 20. Because no video signal processor is connected to the front stage of the slave video signal processor 18, there is no data to be transferred to the slave video signal processor 20 through a second bypass channel V2.

On the other hand, video signals captured by four video cameras vc5-vc8 are converted into digital video data by A/D converters 12. Then, the digital video data is inputted into a video source channel coupled to the slave video signal processor 20. Then, the slave video signal processor 20 reduces and outputs the video data appropriate to configure the four divided display screens. The reduced video data is outputted to the first bypass channel V3 (vc5-vc8) through input buffers 34 and then transferred to the slave video signal processor 22. After processing the video signals captured by the video cameras vc1-vc4, the slave video signal processor 20 receives the digital video data through the first bypass channel V1 coupled to the slave video signal processor 18 placed at its front stage. The digital video data is transferred to the second bypass channel V4 (vc1-vc4) through the bypass buffer 42.

After processing video signals captured by the video cameras vc5-vc8, the slave video signal processor 22 receives the reduced video data through the first bypass channel V3. Further, after processing video signals captured by the video cameras vc1-vc4, the slave video signal processor 22 receives the reduced video data through the second bypass channel V4. The video data outputted from two bypass channels V3 and V4 is collected in the bypass buffer 42 and then transferred to the master video signal processor 24 through the second bypass channel V6 (vc1-vc8). The digital video data inputted into the video source channel coupled to the slave video signal processor 22 is transferred to the master video signal processor 24 through the first bypass channel V5 (vc9-vc12) according to the above described operation.

Accordingly, the bypass buffer 42 within the master video signal processor 24 collects the digital video data (vc1-vc12) inputted through the first bypass channel V5 and the second bypass channel V6 and then outputs it to the memory controller 36. The digital video data of the video source channel corresponding to the video signals captured by the video cameras vc13-vc16 is reduced and then transferred to the memory controller 36. The memory controller 36 within the master video signal processor 24 records and stores the digital video data of sixteen channels at designation addresses of the frame memory 26, thereby configuring the sixteen divided display screens. The video data corresponding to the sixteen divided display screens stored in the frame memory 26 is accessed by the memory controller 36 and then transferred to an external D/A converter 28 through the video output controller 40, thereby displaying the sixteen divided display screens on the video display device.

Because the present invention does not have to configure frame memories within every video signal processor for configuring sixteen divided display screens and also does not have to configure an additional video signal processor for configuring the sixteen divided display screens at a last stage of a video monitoring system, the system can be simply configured.

Further, because video signal processors having the same components as one another are alternatively employed as a slave video signal processor or master video signal processor, the construction of the system can be facilitated and the system can be simply extended or reduced.

Although the video monitoring system configuring and displaying the sixteen divided display screens has been described above, it can display twelve divided display screens by coupling two slave video signal processors 18 and 20 and one master video signal processor 24 through the daisy chain as shown in FIG. 6. Further, the video monitoring system can display eight divided display screens by coupling one slave video signal processor 18 and one master video signal processor 24 through daisy chain as shown in FIG. 7.

Therefore, the present invention is not limited to the above-described embodiments, but the present invention is defined by the claims which follow, along with their full scope of equivalents.

Because the present invention does not have to configure frame memories within every video signal processor for configuring sixteen divided display screens and also does not have to configure an additional video signal processor for configuring the sixteen divided display screens at a last stage of a system, the system can be simply configured.

Further, because video signal processors having the same components as each other are alternatively employed as a slave video signal processor or master video signal processor, the construction of the system can be facilitated and the system can be simply extended or reduced. 

1. An image processing device, comprising: at least one video input controller for receiving at least one set of digital video data, extracting a synchronous signal from the digital video data, separating the digital video data into luminance component data and chrominance component data, and outputting the synchronous signal and the separated data; at least one horizontal/vertical scaler for variably downscaling a screen on which to display the video data outputted from the video input controller, in a horizontal and/or a vertical direction according to the number of divided display screens; at least one input buffer for temporarily storing the screen-downscaled digital video data and then inputting the stored data into a first bypass channel; and a bypass buffer for collecting first input video data and second input video data, each having a plurality of sets of video data which number as many as the downscaled screens and outputting the collected video data through a second bypass channel.
 2. An image processing device, comprising: at least one video input controller for receiving at least one set of digital video data, extracting a synchronous signal from the digital video data, separating the digital video data into luminance component data and chrominance component data, and outputting the synchronous signal and the separated data; at least one horizontal/vertical scaler for variably downscaling a screen on which to display the video data outputted from the video input controller, in a horizontal and/or a vertical direction according to the number of divided display screens; at least one input buffer for temporarily storing the screen-downscaled digital video data and then transferring the stored data into a memory controller; a bypass buffer for collecting first input video data and second input video data, each having a plurality of sets of video data which number as many as the downscaled screens and transferring the collected video data to the memory controller; and a memory controller for recording the screen-downscaled digital video data from the input buffer and the digital video data collected from the bypass buffer at respective designated frame memory addresses to configure multi-channel divided screen data, and reading out and displaying the recorded data.
 3. The image processing device as set forth in claim 2, further comprising: an output buffer for temporarily storing the video data of one display screen outputted from the memory controller; and a video output controller for combining supplementary information with the video data of one display screen outputted from the output buffer and outputting the video data and the supplementary information. 